Changes in the seasonality of mortality in Germany from 1946 to 1995: the role of temperature

Based on records from the Federal Bureau for Statistics of Germany, the sea sonality of mortality was investigated for the period 1946-1995. Lowest mor tality rates were found during summer (August or September) while highest v alues were found in winter (January through March). Non-linear regression o f all monthly mortality data with the average monthly temperatures in Germa ny revealed a significant negative relationship (r=-0.739; n=600; P<0.0001) . The fact that the differences between the long-range monthly temperatures and the individual monthly temperatures also showed a distinct relationshi p to the mortality rates speaks against a mere coincidence of both paramete rs. The amplitude of this seasonal rhythm declined steadily within the obse rvation period. It is concluded that low temperatures cause an increase in mortality rates and that this effect has become less important during recen t decades due to the increased use of central heating and because of improv ements in the public health system.